parse_length_equal
if (!parse_length_equal(p, "private key",
if (!parse_length_equal(p, "shared secret",
if (!parse_length_equal(p, "seed", MLKEM_SEED_LENGTH, CBS_len(&seed)))
if (!parse_length_equal(p, "public key",
if (!parse_length_equal(p, "private key",
if (!parse_length_equal(p, "bogus z or d", MLKEM_SEED_LENGTH, seed_len))
if (!parse_length_equal(p, descr, CBS_len(want), got_len))
int parse_length_equal(struct parse *p, const char *descr, size_t want, size_t got);